You can add Mint repos to Ubuntu, too, and get Mint Menu, MGSE etc. There is not need to re-install if you are an Ubuntu or Mint user. You can
have your cake and eat it too. +Naveed H.
If anybody wants to try Unity, do not
start with 11.04. It is poor. It is okay in 11.10 and rocks in 12.04. It is faster. It is more customisable. It has more features. On 12.04 you can at last see where Ubuntu is headed, whereas with 11.04 you thought they were shooting themselves in the foot.
Comparisons to GNOME Shell do not work. You either like working full screen for everything or not. I do not, so am not a GS fan. I have a big monitor and I do not need to see huge icons and large text. I am a busy guy and my work habits reflect that. I have lots happening at once and do not need to be pressing extra keys to see them. I like to see a lot at once. Unity at least allows me to have multiple windows open on the same screen. It is the global menu that messes that up so I uninstall it.
I am a KDE user and will not likely switch, but I run Unity ever couple of weeks for a week at a time and it is growing on me. I really customise it though. I will not use the global menu.
I like Fedora, but since it is big on GNOME and I am not then I will run Kubuntu which has had its strings cut from Canonical (a good thing). If I was not so heavily invested (time and commitment) in Kubuntu then I might consider Fedora, but their KDE community is tiny in comparison.